Method for producing needle-equipped outer tube and needle-equipped outer tube

ABSTRACT

A method of manufacturing a needle-equipped outer tube includes a preheating step comprising heating a distal end connecting section to a temperature at or below a softening point of a material forming an outer tube member with a joint member inserted in a distal end connecting section of the outer tube member, and with a needle being inserted or inserted and fixed in the needle insertion hole; and a joint member welding step, performed after the preheating step, comprising thermally welding the joint member to the distal end connecting section of the outer tube member with a distal end portion of the joint member pressed toward the proximal end of the joint member by a pushing member with a pressing force in a range of 4 N to 30 N.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/846,597, filed on Sep. 4, 2015, which is a continuation applicationof and claims the benefit of priority from International PatentApplication No. PCT/JP2013/056318, filed on Mar. 7, 2013. The contentsof these applications are incorporated herein by reference in theirentireties.

BACKGROUND Technical Field

The present disclosure relates to a needle-equipped outer tube in whicha needle of a syringe is directly joined to a distal end of an outertube of the syringe in advance, and a method of manufacturing theneedle-equipped outer tube.

Background Art

In some syringes having a small volume used for insulin administrationor vaccination, a needle-equipped outer tube in which a needle of thesyringe is directly joined to the distal end of the outer tube of thesyringe in advance is used. As a method of manufacturing such aneedle-equipped outer tube, a method of joining a needle to the distalend of an outer tube with an adhesive or the like, a method of joining aneedle to the distal end portion of an outer tube by insert molding, anda method of joining a needle to an outer tube by thermal welding areknown (see, JP 2005-342100 A). Further, a method of pressingly insertinga cylindrical joint member, which is interpositioned between a needleand an outer tube, into the outer tube to assemble together the needle,the outer tube, and the joint member is known (see JP 2004-154210 A).

When using such a joint member, it is preferable to use a method ofthermally welding the joint member to an outer tube such that, using ajoint member having a tapered portion in which the outer diameterdecreases from the distal end side toward the proximal end side and anouter tube including a distal end connecting section having a taperedhollow configured to receive the tapered portion of the joint member,the tapered portion is thermally welded to the tapered hollow with thejoint member pressed to the outer tube toward the proximal end side ofthe joint member. In a thermal welding step, the entire contact surfacebetween the joint member and the outer tube need not be thermallywelded, if a thermally welded section having an annular shape is formed.In this case, a portion of the outer tube making contact with the jointmember includes a non-thermal-weld section which is not heated above thesoftening point and is not thermally welded to the joint member.

Further, in the thermal welding step, when the entire joint member isheated above a certain degree, a distal end portion of the joint memberwhich is not yet inserted in the tapered hollow of the outer tubesoftens and deforms, and thereby may increase its diameter to be largerthan the inner diameter of the opening of the tapered hollow. When suchdeformation occurs, the deformed portion cannot advance into the taperedhollow. This makes it difficult to perform thermal welding between thesurfaces of the tapered portion and the tapered hollow which are inpressed contact with each other, and thus to improve sureness of weldingbetween the joint member and the outer tube. For this reason, it ispreferable that a portion of the joint member not close to the distalend, for example a middle section, is sufficiently heated to bethermally welded in a reliable manner, but the heated area is restrictedto avoid softening of the distal end portion of the joint member.Therefore, the portion of the outer tube making contact with the jointmember includes a portion which makes contact but is a non-thermal-weldsection. Another problem is that a portion which makes contact but is anon-thermal-weld section causes a crack after the needle-equipped outertube is manufactured.

SUMMARY

Embodiments of the present invention are made in view of the problem.For a needle-equipped outer tube including a needle, a joint memberhaving a needle insertion hole penetrating the joint member from thedistal end to the proximal end and allowing the needle to be insertedtherein and a tapered portion of which the outer diameter decreases fromthe distal end side toward the proximal end side, and an outer tubeincluding a distal end connecting section having a tapered hollowconfigured to receive the tapered portion of the joint member, and amethod of manufacturing the needle-equipped outer tube, an object ofcertain embodiments of the present invention is to provide a method ofmanufacturing a needle-equipped outer tube that can avoid generation ofcracks, and a needle-equipped outer tube manufactured by that method ofmanufacturing.

In one embodiment, a method of manufacturing a needle-equipped outertube including a needle, a joint member having a needle insertion holepenetrating the joint member from a distal end to a proximal end so asto allow the needle to be inserted therein and a tapered portion inwhich an outer diameter decreases from a distal end side toward aproximal end side, and an outer tube member including a distal endconnecting section having a tapered hollow configured to receive thetapered portion of the joint member includes a preheating stepcomprising heating the distal end connecting section to a temperature ator below a softening point of a material forming the outer tube memberwith the joint member inserted in the distal end connecting section ofthe outer tube member, and with the needle being inserted or insertedand fixed in the needle insertion hole; and a joint member welding step,performed after the preheating step, comprising thermally welding thejoint member to the distal end connecting section of the outer tubemember with a distal end portion of the joint member pressed toward theproximal end of the joint member by a pushing member with a pressingforce in a range of 4 N to 30 N.

In one aspect, the heating in the preheating step is performed at atemperature higher than a glass-transition point of the material formingthe outer tube member.

In one aspect, the heating in the preheating step is performed at atemperature in a range of 110° C. to 150° C.

In one aspect, a material forming the joint member and the materialforming the outer tube member are thermoplastic resins havingcompatibility with each other when melting.

In one aspect, the material forming the joint member and the materialforming the outer tube member are a same thermoplastic resin or comprisea same base thermoplastic resin.

In one aspect, the material forming the joint member and the outer tubemember is cyclic olefin polymer.

In another embodiment, a needle-equipped outer tube includes a needle; ajoint member having a needle insertion hole penetrating the joint memberfrom a distal end to a proximal end and allowing the needle to beinserted therein and a tapered portion in which an outer diameterdecreases from a distal end side toward a proximal end side; and anouter tube member including a distal end connecting section having atapered hollow configured to receive the tapered portion of the jointmember. The joint member is disposed in the hollow of the distal endconnecting section of the outer tube member and fixed to the distal endconnecting section by a thermal-weld section formed at a locationseparated from a distal end of the distal end connecting section by apredetermined distance toward a proximal end. The distal end connectingsection has a contact section, which is a non-thermal-weld section thatcontacts the joint member, at a location closer to the distal end thanthe thermal-weld section, the contact section including a residualstrain but no crack.

In one aspect, the outer tube is manufactured by the method according toclaim 1.

In one aspect, the contact section has a phase difference inbirefringence measurement due to the residual strain, and an occurrencefrequency of a phase difference exceeding 800 nm in birefringencemeasurement is equal to or smaller than one tenth of an occurrencefrequency of a phase difference smaller than 800 nm.

In one aspect, a phase difference exceeding 900 nm does not occur inbirefringence measurement in the contact section.

In one aspect, the contact section has a peak in an occurrence frequencyin a range of 100 nm to 500 nm of a phase difference in birefringencemeasurement.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of a needle-equipped outer tube according to anembodiment of the present invention.

FIG. 2 is a plan view of the needle-equipped outer tube according to anembodiment of the present invention.

FIG. 3 is a cross sectional view of the needle-equipped outer tubeillustrated in FIG. 2 taken along the line A-A.

FIG. 4 is an enlarged longitudinal cross sectional view of an essentialportion of the needle-equipped outer tube according to an embodiment ofthe present invention.

FIG. 5 is a longitudinal cross sectional view of an outer tube.

FIG. 6 is an enlarged front view of a joint member.

FIG. 7 is a plan view of the joint member illustrated in FIG. 6.

FIG. 8 is a longitudinal cross sectional view of the joint memberillustrated in FIG. 6.

FIG. 9 is an exploded perspective view of the needle-equipped outer tubeaccording to an embodiment of the present invention.

FIG. 10 is a front view illustrating a state in which a cap is attachedto the needle-equipped outer tube according to an embodiment of thepresent invention.

FIG. 11 is a cross sectional view of the needle-equipped outer tubeillustrated in FIG. 10 taken along the line B-B.

FIG. 12 is an explanatory drawing explaining preheating step in a methodof manufacturing a needle-equipped outer tube according to an embodimentof the present invention.

FIG. 13 is an explanatory drawing explaining joint member welding stepin the method of manufacturing the needle-equipped outer tube accordingto an embodiment of the present invention.

FIG. 14 is an explanatory drawing explaining a preheating step in amethod of manufacturing a needle-equipped outer tube according toanother embodiment of the present invention.

FIG. 15 is an explanatory drawing explaining a welding step of the jointmember in a method of manufacturing a needle-equipped outer tubeaccording to another embodiment of the present invention.

DETAILED DESCRIPTION

A needle-equipped outer tube according to embodiments of the presentinvention will now be described with reference to the drawings.

A needle-equipped outer tube 1 according to an embodiment of the presentinvention includes a needle 3, a joint member 4 having a needleinsertion hole 42 penetrating the joint member 4 from the distal end tothe proximal end and allowing the needle 3 to be inserted therein and atapered portion 47 of which the outer diameter decreases from the distalend side toward the proximal end side, an outer tube member 2 includinga distal end connecting section 22 having a tapered hollow 26 configuredto receive the tapered portion 47 of the joint member 4.

The joint member 4 is inserted in the hollow 26 of the distal endconnecting section 22 of the outer tube member 2 and fixed to the distalend connecting section 22 by a thermal-weld section 45 formed at alocation away from the distal end of the distal end connecting section22 by a predetermined distance toward the proximal end.

The distal end connecting section 22 has a contact section 46 closer tothe distal end than the thermal-weld section 45. The contact section 46is a non-thermal-weld section and makes contact with the joint member 4.The contact section 46 includes residual strain but no crack.

The needle-equipped outer tube according to the present embodiment isused for carrying out piercing from the surface of a skin with a needletip to inject medicine into a living body.

As illustrated in FIGS. 1 to 4, the needle-equipped outer tube 1according to the embodiment includes the needle 3, the joint member 4 towhich the needle 3 is joined, and the outer tube member 2 to which thejoint member 4 is joined. A cap 6 is attached to the needle-equippedouter tube 1 as illustrated in FIGS. 10 and 11.

As illustrated in FIGS. 1, 3, and 9, a needle having a gauge size of 27to 30 (outer diameter of ϕ0.41 to ϕ0.31 mm) according to ISO standardsfor medical needles (ISO9626: 1991/Amd. 1:2001(E)) is used as the needle3.

On one end in the axial direction of the needle 3, a needle tip 32 whichis to be pierced into a living body is formed. The needle tip 32 isformed to have an acute angle forming a bladed edge. The needle 3 has alength such that the needle 3 is disposed in the distal end connectingsection 22, which will be described later, of the outer tube member 2with the needle tip 32 protruding from a distal end sleeve (distal endportion) 43, which will be described later, of the joint member 4 and aproximal end 33 of the needle 3 opposite to the needle tip 32 protrudingfrom a tapered portion 47, which will be described later, of the jointmember 4.

A middle section 31 of the needle 3 is inserted in the needle insertionhole 42, which will be described later, of the joint member 4. At leastthe surface of the middle section 31 of the needle 3 is a rough surfaceroughened by blasting or the like. This enhances the joining strengthbetween the needle 3 and the joint member 4 by the softened resinintruding into irregularities on the rough surface of the needle 3 whenthe needle 3 and the joint member 4 are joined by thermal welding.Furthermore, intruding of the softened resin into irregularities on therough surface of the needle 3 can improve water-tightness.

The material of the needle 3 is preferably, for example, a stainlesssteel. Although, the material is not limited to a stainless steel, andmay be other metal materials such as aluminum, an aluminum alloy,titanium, and a titanium alloy. Not only a straight needle, but atapered needle at least a portion of which is tapered can be used as theneedle 3. The needle 3 may have a circular cross section, oralternatively, a polygonal cross section, such as a triangular crosssection. A coating material formed of, for example, a silicone resin ora fluorine-based resin may be applied to the surface of a portion of theneedle 3 in the needle tip 32 side.

The joint member 4 will now be described. As illustrated in FIGS. 6 to8, the joint member 4 is configured with the distal end sleeve (distalend portion) 43 and a proximal end sleeve 41 that is smaller in outerdiameter and larger in length than the distal end sleeve 43. The distalend sleeve 43 is formed in a cylindrical shape having approximatelyconstant outer diameter. The outer surface of the proximal end sleeve 41composes a tapered portion 47 that is formed to have a tapered shape ofwhich the outer diameter continuously decreases toward the proximal endside of the joint member 4. The tapered portion 47 is formed to have aradial cross section of a circular shape. In the embodiment, inparticular, the cross section is formed to be an approximately truecircle. As will be described later, the tapered shape of the taperedportion 47 and the tapered shape of the tapered hollow 26 of the distalend connecting section 22 of the outer tube member 2 are approximatelyidentical. This means that the tapered portion 47 is formed to have ashape which allows almost the entire surface of the tapered portion 47to make contact with the entire surface of the tapered hollow 26 whenthe tapered portion 47 is inserted in the tapered hollow 26. The taperedportion 47 is formed in a shape that can be engaged in the taperedhollow 26.

The joint member 4 is provided with the needle insertion hole 42 inwhich the needle 3 is inserted. The needle insertion hole 42 has aninner diameter larger than the outer diameter of the needle 3 by about0.02 to 0.14 mm, preferably, about 0.02 to 0.11 mm. When theaforementioned needle 3 having a gauge size of 27 to 30 is used, the gapwith respect to the needle 3 can be achieved as described above byproviding the needle insertion hole 42 with the inner diameter of 0.43to 0.45 mm. By determining the configuration as described above, joiningstrength of the joined needle 3 can be secured and tilting of the joinedneedle 3 at a predetermined degree or more can be prevented. Thedistance from the outer surface of the joint member 4 to the needleinsertion hole 42, namely the thickness, is provided to be 0.38 to 0.48mm. By using the single joint member 4 in such a configuration, theneedle-equipped outer tube 1 using any of the needles 3 having a gaugesize of 27 to 30 that secures joining strength of the needle 3 andprevents the joined needle 3 from tilting at a predetermined degree ormore can be manufactured.

As illustrated in FIG. 8, the distal end portion of the needle insertionhole 42 (the inside of the distal end sleeve 43) is a large-diameterportion 44 having a larger diameter than the other portion. A graduallyprotruding annular rib 48 is formed in the portion located somewhat inthe proximal end side from the distal end (opened end) of thelarge-diameter portion 44. The annular rib 48 has gradual inclinedsurface on both sides of the top of the ridge. A tapered portion 49 ofwhich diameter decreases is provided in the proximal end side of theannular rib 48 so as to continue to the proximal end of the annular rib48.

As materials forming the joint member 4 and the outer tube member 2,which will be described later, various types of resin such as polyvinylchloride, polyethylene, polypropylene, cyclic olefin polymer,polystyrene, poly(4-methylpentene-1), polycarbonate, acrylic resin,acrylonitrile-butadiene-styrene copolymer, polyester such aspolyethylene-terephthalate, butadiene-styrene copolymer, and polyamide(e.g., nylon 6, nylon 6,6, nylon 6,10, nylon 12) may be used. Amongthose, a resin such as polypropylene, cyclic olefin polymer, polyester,and poly(4-methylpentene-1) is preferably used. It is preferable thatmaterials forming the joint member 4 and the outer tube member 2 aresubstantially transparent so that the inside thereof is visible.

The outer tube member 2 will now be described. As illustrated in FIG. 5,the outer tube member 2 includes an outer tube body 21 which is to befilled with medicine and the distal end connecting section 22 to whichthe joint member 4 is joined. The outer tube body 21 is formed to havean approximately cylindrical shape including an internal container. Aflange 23 is formed in the proximal end side in the axial direction ofthe outer tube body 21.

The distal end connecting section 22 is configured with a taperedengagement portion 24 continuing to the outer tube body 21 and a distalend engagement portion 25 continuing to the tapered engagement portion24. The tapered engagement portion 24 is formed to have an approximatelycross-shape in a radial cross section. In other words, four ribsextending along the axial direction are provided. The tapered hollow 26which continuously increases in diameter toward the distal end andreceives the tapered portion 47 of the joint member 4 described above toengage therewith by tapered surfaces is formed inside the taperedengagement portion 24. The tapered hollow 26 is formed to have acircular shape in a radial cross section. The outer tube of theembodiment, in particular, is formed to have a cross section of anapproximately true circle. The thickness of the tapered engagementportion 24 where no rib exists is preferably 0.8 to 1.1 mm, morepreferably, 0.9 to 1.05 mm.

The tapered hollow 26 and the tapered portion 47 have approximatelyidentical tapered shapes. A distal end side engagement hole 28 formed ina column shape and communicating with the tapered hollow 26 is providedinside the distal end engagement portion 25. The distal end sideengagement hole 28 is formed to have a larger diameter than the taperedhollow 26. The taper angles of the tapered hollow 26 and the taperedportion 47 of the joint member 4 are not particularly limited but maypreferably be 1 to 3 degrees. As illustrated in FIG. 4, the distal endside engagement hole 28 has approximately the same diameter as thedistal end sleeve 43 of the joint member 4 to engage with andaccommodate the distal end sleeve 43.

In the embodiment, the outer tube body 21 having an approximatelycylindrical shape is exemplarily described. Although, the outer tubebody 21 may be formed in a hollowed shape of a square pillar or ahexagonal pillar.

The material of the outer tube member 2 may preferably be selected frommaterials having compatibility with the material forming the jointmember 4.

In particular, as will be described later, the distal end connectingsection 22 of the outer tube member 2 is joined with the joint member 4by thermal welding. Therefore, it is preferable that the material of theouter tube member 2 and the material of the joint member 4 aresubstantially the same. In this manner, preferable bondability betweenthe distal end connecting section 22 and the joint member 4 can beobtained, so that the distal end connecting section 22 and the jointmember 4 can firmly be fixed. Moreover, the welded portion between thedistal end connecting section 22 and the joint member 4 can be madeinconspicuous, so that aesthetic of the needle-equipped outer tube 1 canbe improved.

The needle 3, the joint member 4, and the outer tube member 2 are weldedby a method of manufacturing as illustrated in FIGS. 1 to 4, which willbe described later, to constitute the needle-equipped outer tube 1. Asillustrated in FIG. 4, the joint member 4 is fixed to the inside of thetapered hollow 26 inside the distal end connecting section 22 by thethermal-weld section 45 formed at a location away from the distal end ofthe distal end connecting section 22 of the outer tube member 2 by apredetermined distance toward the proximal end. The outer tube accordingto the present embodiment has no bubble included in and near thethermal-weld section 45. Thus no fragile portion resulting from bubblesexists.

The distal end connecting section 22 has in the distal end side of thethermal-weld section 45 the contact section 46, which is anon-thermal-weld section, which is not thermally welded but makescontact with the joint member 4. As will be described later, by havingthe contact section 46, which is a non-thermal-weld section, only theportion in a distal side of the joint member 4 is heated to be welded sothat the portion of the joint member 4 in the side to the distal enddoes not soften and deform.

In the outer tube according to the present embodiment, the contactsection 46 includes residual strain but no crack. The outer tube thatincludes the contact section 46, which is a non-thermal-weld sectionmaking contact with the joint member 4, including residual strain but nocrack can be manufactured by a method of manufacturing theneedle-equipped outer tube which will be described later.

Furthermore, it is preferable that the contact section 46 has a phasedifference due to residual strain in birefringence measurement where theoccurrence frequency of a phase difference exceeding 800 nm inbirefringence measurement is equal to or smaller than one tenth of theoccurrence frequency of a phase difference smaller than 800 nm. Indifferent words, it is preferable that, in a predetermined area in avertical cross section of the outer tube in the contact section 46, thearea where a phase difference is 800 nm or larger is 10% or less than10% of the predetermined area.

For “phase difference”, an in-plane birefringence phase difference inunit thickness for incident light entering a portion of the contactsection 46 along the radial direction of the distal end connectingsection 22 is used. The phase difference is obtained from two types ofproperty data, which are data on retardation (birefringence phasedifference) property Re measured with a two-dimensional birefringencemeasuring device and data on distribution on plane of axial (phaseadvancing axis, phase delaying axis) angles. The phase difference(in-plane phase difference) can be measured using a commerciallyavailable phase difference measuring device (e.g., WPA-100 manufacturedby Photonic Lattice Inc., KOBRA-21ADH manufactured by Oji ScientificInstruments Co., Ltd.) or by Senarmont method.

When the occurrence frequency of a phase difference exceeding 800 nm inbirefringence measurement is equal to or smaller than one tenth of theoccurrence frequency of a phase difference below 800 nm, the contactsection 46 includes residual strain but no portion that largely deforms(for example, a crack or a portion which causes a crack).

In particular, the contact section 46 in which a phase differenceexceeding 900 nm does not occur in birefringence measurement ispreferable. In different words, it is preferable that a predeterminedarea in a vertical cross section of the outer tube in the contactsection 46 substantially has no area where a phase difference is 900 nmor larger. Furthermore, the contact section 46 having a peak inoccurrence frequency of phase difference within the range from 100 nm to500 nm in birefringence measurement is preferable.

A syringe 10 using the needle-equipped outer tube 1 according to anembodiment of the present invention will now be described.

As illustrated in FIG. 10, the syringe 10 includes the needle-equippedouter tube 1 described above, the cap 6 attached to the distal endportion (needle) of the outer tube 1, a gasket 5 contained in the outertube 1 to slide thereinside, and a plunger 7 attached to the gasket 5.The plunger 7 includes a plunger body 71, a gasket-attach portion formedin the distal end of the plunger body 71, and a pusher 73 provided inthe proximal end portion. The gasket has a plunger-attach portion whichreceives and engages with a gasket-attach portion 72 of the plunger 7.

The cap 6 is formed in a cylindrical shape. A proximal portion 61 in theaxial direction is opened and the distal end in the axial direction isclosed. The cap 6 is formed of an elastic member, for example, a rubberor an elastomer. The cap 6 is attached to the distal end connectingsection 22 of the outer tube member 2 so as to cover the needle tip 32of the needle 3 and the distal end connecting section 22 of the outertube member 2. As illustrated in FIG. 11, the needle 3 and the distalend connecting section 22 are inserted in an internal space 62 of thecap 6.

The inner diameter of the internal space 62 of the cap 6 is formedapproximately identical to the outer diameter of the distal endengagement portion 25 of the distal end connecting section 22 orslightly smaller than the outer diameter of the distal end engagementportion 25. Thus when the cap 6 is attached to the distal end connectingsection 22, the outer circumferential surface of the distal endengagement portion 25 makes tight contact with the inner circumferentialsurface of the cap 6. In this manner, the space surrounding the needle 3protruding from the joint member 4 is sealed by the distal endengagement portion 25 and the inner circumferential surface of the cap6. This configuration prevents adherence of germs to the needle tip 32.At the same time, the needle tip holder 63 holds the needle tip 32.

The elastic force of the inner circumferential surface of the cap 6constricts the necked portion at the boundary between the distal endengagement portion 25 and the tapered engagement portion 24 of thedistal end connecting section 22. With the inner circumferential surfaceof the cap 6 engaging with the necked portion of the distal endconnecting section 22, the cap 6 coming off from the distal endconnecting section 22 during transportation can be prevented.

A method of manufacturing the needle-equipped outer tube 1 will now bedescribed.

The method of manufacturing the needle-equipped outer tube according toan embodiment of the present invention is of manufacturing theneedle-equipped outer tube that includes the contact section 46, whichis a non-thermal-weld section as described above making contact with thejoint member 4, including residual strain but no crack.

In the method of manufacturing the needle-equipped outer tube accordingto the present embodiment, a preheating step is performed to heat thedistal end connecting section 22 to a temperature at or below thesoftening point of a material forming the outer tube with the jointmember 4 inserted in the distal end connecting section 22 of the outertube member 2, with the needle 3 being inserted or inserted and fixed inthe needle insertion hole 42, and a joint member welding step isperformed after the preheating step to thermally weld the joint member 4to the distal end connecting section 22 of the outer tube member 2 withthe distal end portion of the joint member 4 pressed toward the proximalend of the joint member 4 by a pushing member 17 with a pressing forceof 4 N to 30 N.

To manufacture the needle-equipped outer tube 1 according to anembodiment of the present invention, the needle 3, the joint member 4,and the outer tube member 2 are each prepared as illustrated in FIG. 9.The needle 3 is formed in a desired tubular body by, for example, pressforming a sheet metal or swaging a hollow pipe. The joint member 4 andthe outer tube member 2 are formed by injection molding. By separatelyforming the joint member 4 and the outer tube member 2, dies can bedownsized and simplified.

Then an engagement step is performed to engage together the needle 3,the joint member 4, and the outer tube member 2. In the engagement step,the joint member 4 is inserted in the tapered hollow 26 and the distalend side engagement hole 28 of the distal end connecting section 22 ofthe outer tube member 2. When the joint member 4 is pushed in to reachthe proximal end inside the distal end connecting section 22, theproximal end sleeve 41 and the tapered portion 47 of the joint member 4engage in the tapered hollow 26 of the distal end connecting section 22and the distal end sleeve 43 of the joint member 4 engages in the distalend engagement portion 25 of the distal end connecting section 22 of theouter tube member 2. Then an insertion step of the needle 3 isperformed. In the insertion step, the needle 3 is inserted in the needleinsertion hole 42 of the joint member 4, thereby assembling the needle 3to the joint member 4 engaging with the outer tube member 2. Instead ofinserting the needle 3 in the joint member 4 after the engagement stepof engaging the joint member 4 in the outer tube member 2, the needle 3may previously be inserted and fixed in the joint member 4 beforeperforming the engagement step of the joint member 4 and the outer tubemember 2.

In the embodiment as illustrated in FIG. 12, a needle supporting member12 is used for positioning the needle 3 in the joint member 4 and theouter tube member 2. The needle supporting member 12 has on the top asupporting projection 13 to support the proximal end 33 of the needle 3and is disposed inside the internal container of the outer tube body 21.The needle supporting member 12 is disposed so as the supportingprojection 13 to be inserted in the tapered hollow 26 of the distal endconnecting section 22. Thus the proximal end 33 of the needle 3supported by the supporting projection 13 is disposed inside the distalend connecting section 22 so as the needle 3 not to protrude into theinternal container of the outer tube body 21. Consequently, the deadvolume inside the outer tube member 2 can be reduced, thereby reducingthe amount of medicine remaining inside the outer tube member 2.

In the embodiment described above, the needle 3 provided separately fromthe joint member 4 is inserted in the joint member 4 after the jointmember 4 engages in the distal end connecting section 22 and ispositioned by the needle supporting member 12 or the like. However, thisis not the only procedure. The needle 3 and the joint member 4 maypreviously be integrated by insert molding before the engagement stepdescribed above. In such a procedure, positioning of the needle 3 is notnecessary in the joint member welding step.

Then the preheating step is performed. In the preheating step, it ispreferable that heating the distal end connecting section 22 isperformed to a temperature at or below the softening point of thematerial forming the outer tube member 2. In particular, it ispreferable that heating is performed to a temperature from around theglass-transition point to the softening point of the material formingthe outer tube member 2. Specifically, when the outer tube member 2formed of cyclic olefin polymer (COP) is used, the needle-equipped outertube 1 is preferably heated after the insertion step described above toa temperature within a range from 110° C. to 150° C.

For heating means, two halogen heaters 11 disposed in both sides of theouter tube member 2 are preferably used, as illustrated in FIG. 12. Byusing the halogen heaters 11, the contact section 46 of the outer tubemember 2 described above can easily be heated locally. Furthermore,reaching speed of heat in the depth direction can be raised. In theexample needle-equipped outer tube 1 described above, with thepreheating step performed in a short period of 100 W (12 V)×2 seconds(s) can achieve the aforementioned range of heating. In the preheatingstep, the distal end connecting section 22 of the outer tube member 2can uniformly be heated in circumferential direction by rotating theneedle-equipped outer tube 1 about its axis. In the embodiment, thepreheating step is performed for the contact section 46. Although, thepreheating step may be performed for other portions where a crack mightoccur. Alternatively, the preheating step may be performed for the wholedistal end connecting section 22.

The heating means is not limited to the halogen heater 11 describedabove. Other means, such as a carbon heater or hot air may be used. Forexample, when the needle-equipped outer tube 1 is placed inside a boothto be heated by hot air, and, for example, when the needle-equippedouter tube 1 has the same configuration as described above, thetemperature is raised to be within a range from 110° C. to 150° C. byheating 290° C.×6 seconds (S) in the booth.

Then after the preheating step, the joint member welding step isperformed. As illustrated in FIG. 13, in the joint member welding step,the joint member 4 is thermally welded to the distal end connectingsection of the outer tube member 2 with the distal end sleeve (distalend portion) 43 of the joint member 4 pressed toward the proximal end ofthe joint member 4 by the pushing member 17 with a pressing force of 4 Nto 30 N.

The pushing member 17 has an accommodating hole 19 for accommodating theneedle 3 and a pusher 18 for pushing the distal end sleeve 43 of thejoint member 4. By applying pressure on the joint member 4 with thepusher 18, the outer circumferential surface of the tapered portion 47and the inner circumferential surface of the tapered hollow 26 are keptin tight contact with each other in the joint member welding step, andjoining strength between the joint member 4 and the distal endconnecting section 22 of the outer tube member 2 can thereby beimproved.

In the embodiment, thermal welding is performed by using a semiconductorlaser emission apparatus 20. The semiconductor laser emission apparatus20 irradiates the thermal-weld section 45 between the tapered portion 47of the joint member 4 and the tapered hollow 26 of the outer tube member2 with laser. The temperature of the needle 3 is raised and the jointmember 4 is heated. The joint member 4 softens and adheres to the needle3 and the distal end connecting section 22 of the outer tube member 2.As a result, the joint member 4 and the needle 3 as well as the jointmember 4 and the distal end connecting section 22 of the outer tubemember 2 are joined by thermal welding, and the needle-equipped outertube 1 is manufactured. To achieve tight contact between surfaces of thetapered portion 47 and the tapered hollow 26 by the pushing member 17,the outer diameter of the proximal end sleeve 41 of the joint member 4should not deform, by softening, to be larger than the inner diameter ofthe opening of the tapered hollow 26. Therefore, a region to beirradiated by the semiconductor laser emission apparatus is determinedso that only a predetermined region in the thermal-weld section 45 closeto the proximal end of the joint member 4 melts. Laser is emitted to athin portion located between ribs of the tapered engagement portion 24.

Flexibility (deflection) of the needle can be controlled by determiningthe location of the thermal-weld section 45 to be at any portion. Forexample, to prevent kinking (bending) by adjusting the needle to deflecteasily, the thermal-weld section 45 is preferably provided in a regionfrom the middle section to the vicinity of the proximal end of thetapered engagement portion 24, or a region from the middle portion tothe vicinity of the proximal end of the joint member 4. To suppressdeflection, the thermal-weld section 45 is preferably provided in aregion from the middle section to the vicinity of the distal end of thetapered engagement portion 24, or a region from the middle portion tothe vicinity of the distal end of the joint member 4.

When the thickness of the joint member 4 is set to 0.38 to 0.48 mm, andthe thickness of a portion of the tapered engagement portion 24 of theouter tube where no rib exists is set to 0.8 to 1.1 mm, it is preferableto set the output of the semiconductor laser emission apparatus 20within a range from 5 to 20 W and the irradiation time of laser within arange from 1.5 to 2.0 seconds (s). Regarding an optical system, a focusdiameter is preferably set within ϕ3.0 to ϕ3.5 mm. The conditiondescribed above is for a case when cyclic olefin polymer (COP) is usedas the material of the joint member. The condition should be set toachieve an appropriate resin temperature according to the property of aresin to be used so as to prevent foaming, a burnt resin, anddeformation. In the embodiment, the semiconductor laser emissionapparatus 20 is used to join the joint member 4 and the needle 3 as wellas the joint member 4 and the outer tube member 2, so that the needle 3can be fixed to the outer tube member 2 without using an adhesive.

Furthermore in the embodiment, thermal welding is performed with thejoint member 4 pressed by the pushing member 17 along the axialdirection of the outer tube member 2, so that no gap is formed betweenthe joint member 4 and the distal end connecting section 22 of the outertube member 2. In this manner, no foaming occurs in the joint member 4when the joint member 4 is heated. Thus the joint member 4 obtainstransparency without deterioration in aesthetic, and at the same time,the joint member 4 and the needle 3 as well as the joint member 4 andthe distal end connecting section 22 of the outer tube member 2 cantightly be fixed. Furthermore, an injection molded part is far smallerthan that for a case where insert molding of the needle 3 is directlyperformed for the outer tube member 2 during injection molding of theouter tube member 2, so that a molding machine can be downsized, therebyreducing cost of facilities.

Regarding the method of manufacturing the needle-equipped outer tube 1described above, a comparative experiment on changes in phase differencein the contact section 46 for variation of pressing forces applied tothe joint member 4 by the pushing member 17 will now be described. Forthe needle-equipped outer tube 1 configured as described above, a phasedifference in the contact section 46 of the needle-equipped outer tube 1was measured where a pressing force applied to the joint member 4 by thepushing member 17 in the joint member welding step is 30 N (Example 1)or 10 N (Example 2). As a comparative example, a phase difference in thecontact section of the needle-equipped outer tube was measured under apressing force of 100 N. The phase difference was measured by ameasuring method similar to that described above. As a result, forExample 1, in which a pressing force of 30 N was applied, the area wherea phase difference is 800 nm or larger in the contact section 46 wassomewhat below 10%. For Example 2, in which a pressing force of 10 N wasapplied, the area where a phase difference is 800 nm or larger in thecontact section 46 was approximately zero. For the comparative example,in which a pressing force of 100 N is applied, the area where a phasedifference is 800 nm or larger was about 30%.

In the embodiment described above, the needle 3 is positioned by usingthe needle supporting member 12 provided separately from the outer tubemember 2 in the insertion step of the needle 3. Although, the needle 3may be positioned by a configuration different from the configurationdescribed above. As in another embodiment illustrated in FIG. 14, forexample, the needle 3 may be positioned by the needle 3 making contactwith a needle stopper 27 formed inside the distal end connecting section22 of the outer tube member 2. The needle stopper 27 is formed in aring-shaped protrusion which protrudes from the inner surface of thetapered hollow 26. A communication hole 27 a provided in the centralportion of the needle stopper 27 provides communication among theinternal container of the outer tube body 21, the tapered hollow 26 inthe distal end connecting section 22, and the distal end side engagementhole 28. The needle hole of the needle 3 positioned by making contactwith the needle stopper 27 communicates with the internal container ofthe outer tube body 21 via the communication hole 27 a. In this manner,the needle 3 is positioned in the joint member 4 and the outer tubemember 2 with the proximal end 33 of the needle 3 disposed inside thedistal end connecting section 22 but not inside the internal containerof the outer tube body 21. Consequently, the dead volume inside theouter tube member 2 can be reduced, thereby reducing the amount ofmedicine remaining inside the outer tube member 2.

In the joint member welding step in the embodiment described above,welding means is not limited to the semiconductor laser emissionapparatus 20 and other welding means may be used. For example, as inanother embodiment illustrated in FIG. 15, a high frequency inductionheating apparatus 16 may be used to carry out thermal welding. The highfrequency induction heating apparatus 16 includes a work coil 15 and apower source 16 a for supplying an alternative current to the work coil15. When the power source 16 a supplies an alternative current to thework coil 15, magnetic field is generated around the work coil 15 tocreate an eddy current in the needle 3. The temperature of the needle 3is raised and the joint member 4 is heated. The joint member 4 softensand adheres to the needle 3 and the distal end connecting section 22 ofthe outer tube member 2. As a result, the joint member 4 and the needle3 as well as the joint member 4 and the distal end connecting section 22of the outer tube member 2 are joined by thermal welding, and theneedle-equipped outer tube 1 is manufactured.

In the embodiment described above, materials being substantially thesame are used for the outer tube member 2 and the joint member.Alternatively, thermoplastic resins having compatibility with each otherwhen melting may be used as materials for the outer tube member 2 andthe joint member 4. To have compatibility means to havethermodynamically good mutual solubility. In other words, two materialsdo not separate after solidification.

INDUSTRIAL APPLICABILITY

The method of manufacturing the needle-equipped outer tube according toan embodiment of the present invention is provided as described below.

(1) A method of manufacturing a needle-equipped outer tube including aneedle, a joint member having a needle insertion hole penetrating thejoint member from a distal end to a proximal end and allowing the needleto be inserted therein and a tapered portion of which the outer diameterdecreases from the distal end side toward the proximal end side, and anouter tube member including a distal end connecting section having atapered hollow configured to receive the tapered portion of the jointmember, the method of manufacturing the needle-equipped outer tubeincluding a preheating step of heating the distal end connecting sectionto a temperature at or below the softening point of a material formingthe outer tube with the joint member inserted in the distal endconnecting section of the outer tube member, with the needle beinginserted or inserted and fixed in the needle insertion hole, and a jointmember welding step, performed after the preheating step, of thermallywelding the joint member to the distal end connecting section of theouter tube member with a distal end portion of the joint member pressedtoward the proximal end of the joint member by a pushing member with apressing force of 4 N to 30 N.

In the method according to the present embodiment, by performing thepreheating step described above and selecting a low pressing forceapplied to the joint member in the joint member welding step, aneedle-equipped outer tube having an outer tube member with no crack caneasily and surely be manufactured.

Further aspects of the present embodiment are described below.

(2) The method of manufacturing the needle-equipped outer tube accordingto (1) described above, wherein heating in the preheating step isperformed within a range from around a glass-transition point to thesoftening point of the material forming the outer tube member.

(3) The method of manufacturing the needle-equipped outer tube accordingto (1) or (2) described above, wherein heating in the preheating step isperformed under a temperature from 110° C. to 150° C.

(4) The method of manufacturing the needle-equipped outer tube accordingto any one of (1) to (3) described above, wherein the tapered shape ofthe tapered portion of the joint member and the tapered shape of thetapered hollow of the distal end connecting section of the outer tubemember are approximately identical.

(5) The method of manufacturing the needle-equipped outer tube accordingto any one of (1) to (4) described above, wherein a radial cross sectionof the tapered portion of the joint member is a circular shape and theradial cross section of the tapered hollow of the distal end connectingsection of the outer tube member is also a circular shape.

(6) The method of manufacturing the needle-equipped outer tube accordingto any one of (1) to (5) described above, wherein a material forming thejoint member and a material forming the outer tube member arethermoplastic resins having compatibility with each other when melting.

(7) The method of manufacturing the needle-equipped outer tube accordingto any one of (1) to (5) described above, wherein a material forming thejoint member and a material forming the outer tube member are a samethermoplastic resin or same base thermoplastic resins havingcompatibility with each other.

(8) The method of manufacturing the needle-equipped outer tube accordingto any one of (1) to (5) described above, wherein a material forming thejoint member and the outer tube member is cyclic olefin polymer.

The needle-equipped outer tube according to the present invention isprovided as described below.

(9) A needle-equipped outer tube including a needle, a joint memberhaving a needle insertion hole penetrating the joint member from adistal end to a proximal end and allowing the needle to be insertedtherein and a tapered portion of which the outer diameter decreases fromthe distal end side toward the proximal end side, and an outer tubemember including a distal end connecting section having a tapered hollowconfigured to receive the tapered portion of the joint member, whereinthe joint member is inserted in the hollow of the distal end connectingsection of the outer tube member and fixed to the distal end connectingsection by a thermal-weld section formed at a location away from adistal end of the distal end connecting section by a predetermineddistance toward a proximal end, and the distal end connecting sectionhas a contact section, which is a non-thermal-weld section makingcontact with the joint member, in a portion closer to the distal endthan the thermal-weld section, the contact section including residualstrain but no crack.

Since the needle-equipped outer tube according to present invention hasthe contact section described above, welding is surely carried out atthe thermal-weld section and no fragile portion is produced in thecontact section. Thus the needle-equipped outer tube can be used in aserviceable manner.

The embodiment of the needle-equipped outer tube according to thepresent invention may be provided as described below.

(10) The needle-equipped outer tube according to (9) described above,wherein the outer tube is manufactured by the method of manufacturingthe needle-equipped outer tube according to any one of (1) to (8)described above.

(11) The needle-equipped outer tube according to (9) or (10) describedabove, wherein the contact section has a phase difference due toresidual strain in birefringence measurement and occurrence frequency ofa phase difference exceeding 800 nm in birefringence measurement isequal to or smaller than one tenth of occurrence frequency of a phasedifference smaller than 800 nm.

(12) The needle-equipped outer tube according to any one of (9) to (11)described above, wherein a phase difference exceeding 900 nm does notoccur in birefringence measurement in the contact section.

(13) The needle-equipped outer tube according to any one of (9) to (12)described above, wherein the contact section has a peak in occurrencefrequency within a range from 100 nm to 500 nm of phase difference inbirefringence measurement.

What is claimed is:
 1. A needle-equipped outer tube comprising: aneedle; a joint member comprising a needle insertion hole penetratingthe joint member from a distal end to a proximal end, and a taperedportion in which an outer diameter decreases from a distal end sidetoward a proximal end side; and an outer tube member comprising a distalend connecting section having a tapered hollow portion configured toreceive the tapered portion of the joint member, wherein the needle islocated in the needle insertion hole, wherein the joint member comprisesa thermally-welded section that is disposed between an inner surface ofthe tapered hollow portion and an outer surface of the needle at alocation separated from a distal end of the distal end connectingsection by a predetermined distance toward a proximal end of the distalend connecting section, wherein the joint member does not include afoamed portion.
 2. The needle-equipped outer tube according to claim 1,wherein both the joint member and the outer tube member are formed of athermoplastic resin material.
 3. The needle-equipped outer tubeaccording to claim 2, wherein both the joint member and the outer tubemember are formed of the same thermoplastic resin material.
 4. Theneedle-equipped outer tube according to claim 3, both the joint memberand the outer tube member are formed of cyclic olefin polymer.
 5. Theneedle-equipped outer tube according to claim 1, wherein the distal endconnecting section has a contact section, which is anon-thermally-welded section that contacts the joint member but is notthermally welded to the joint member, at a location distal of thethermally-welded section, the contact section comprising a residualstrain but no crack.
 6. The needle-equipped outer tube according toclaim 5, wherein the contact section has a phase difference inbirefringence measurement due to the residual strain, and an occurrencefrequency of a phase difference exceeding 800 nm in birefringencemeasurement is equal to or smaller than one tenth of an occurrencefrequency of a phase difference smaller than 800 nm.
 7. Theneedle-equipped outer tube according to claim 6, wherein a phasedifference exceeding 900 nm does not occur in birefringence measurementin the contact section.
 8. The needle-equipped outer tube according toclaim 6, wherein the contact section has a peak in an occurrencefrequency in a range of 100 nm to 500 nm of a phase difference inbirefringence measurement.
 9. The needle-equipped outer tube accordingto claim 1, wherein the thermally-welded section is disposed at alocation separated from the proximal end of the distal end connectingsection by a predetermined distance toward the distal end of the distalend connecting section.
 10. The needle-equipped outer tube according toclaim 1, wherein the joint member comprises a distal end portion havinga cylindrical shape, and a proximal end portion comprising the taperedportion.
 11. The needle-equipped outer tube according to claim 1,wherein the needle insertion hole comprises a distal end portion thathas a larger diameter than a portion proximal of the distal end portion.